Buggy code:
public class HashGroupify implements IHashGroupify { public static class GroupStatistics { private double averageEquivalenceClassSize ; private int maximalEquivalenceClassSize ; private int minimalEquivalenceClassSize ; private double averageEquivalenceClassSizeIncludingOutliers ; private int maximalEquivalenceClassSizeIncludingOutliers ; private int minimalEquivalenceClassSizeIncludingOutliers ; private int numberOfGroups ; private int numberOfOutlyingEquivalenceClasses ; private int numberOfOutlyingTuples ; protected GroupStatistics ( double averageEquivalenceClassSize , int maximalEquivalenceClassSize , int minimalEquivalenceClassSize , double averageEquivalenceClassSizeIncludingOutliers , int maximalEquivalenceClassSizeIncludingOutliers , int minimalEquivalenceClassSizeIncludingOutliers , int numberOfGroups , int numberOfOutlyingEquivalenceClasses , int numberOfOutlyingTuples ) { } public double getAverageEquivalenceClassSize ( ) { } public double getAverageEquivalenceClassSizeIncludingOutliers ( ) { } public int getMaximalEquivalenceClassSize ( ) { } public int getMaximalEquivalenceClassSizeIncludingOutliers ( ) { } public int getMinimalEquivalenceClassSize ( ) { } public int getMinimalEquivalenceClassSizeIncludingOutliers ( ) { } public int getNumberOfGroups ( ) { } public int getNumberOfOutlyingEquivalenceClasses ( ) { } public int getNumberOfOutlyingTuples ( ) { } } private boolean kAnonymous ; private boolean anonymous ; private int currentOutliers ; private int elementCount ; private HashGroupifyEntry [ ] buckets ; private HashGroupifyEntry firstEntry ; private HashGroupifyEntry lastEntry ; private final float loadFactor = 0.75F ; private int threshold ; private final int absoluteMaxOutliers ; private final int k ; private final RowSet subset ; private final boolean dpresence ; private final PrivacyCriterion [ ] classBasedCriteria ; private final SampleBasedPrivacyCriterion [ ] sampleBasedCriteria ; public HashGroupify ( int capacity , final ARXConfigurationInternal config ) { } @ Override public void addAll ( int [ ] key , int representant , int count , int [ ] sensitive , int pcount ) { } @ Override public void addGroupify ( int [ ] key , int representant , int count , Distribution [ ] distributions , int pcount ) { } @ Override public void addSnapshot ( int [ ] key , int representant , int count , int [ ] [ ] elements , int [ ] [ ] frequencies , int pcount ) { } @ Override public void analyze ( boolean force ) { } @ Override public void clear ( ) { } @ Override public HashGroupifyEntry getFirstEntry ( ) { } @ Override public HashGroupify . GroupStatistics getGroupStatistics ( ) { } @ Override public boolean isAnonymous ( ) { } @ Override public boolean isKAnonymous ( ) { } @ Override public void markOutliers ( final int [ ] [ ] data ) { } public void resetSuppression ( ) { } @ Override public int size ( ) { } private final HashGroupifyEntry addInternal ( final int [ ] key , final int hash , final int representant , int count , final int pcount ) { } private void analyzeAll ( ) { } private void analyzeWithEarlyAbort ( ) { kAnonymous = ( currentOutliers ) <= ( absoluteMaxOutliers ) ; <START_BUG> if ( ( classBasedCriteria . length ) == 0 ) { <END_BUG> anonymous = kAnonymous ; return ; } if ( ( ( k ) != ( Integer . MAX_VALUE ) ) && ( ! ( kAnonymous ) ) ) { anonymous = false ; return ; } currentOutliers = 0 ; HashGroupifyEntry entry = firstEntry ; while ( entry != null ) { int anonymous = isAnonymous ( entry ) ; if ( anonymous != ( - 1 ) ) { if ( ( ( dpresence ) && ( ( entry . count ) == 0 ) ) && ( anonymous == 1 ) ) { this . anonymous = false ; return ; } currentOutliers += entry . count ; if ( ( currentOutliers ) > ( absoluteMaxOutliers ) ) { this . anonymous = false ; return ; } } entry . isNotOutlier = ( ( entry . count ) != 0 ) ? anonymous == ( - 1 ) : true ; entry = entry . nextOrdered ; } this . analyzeSampleBasedCriteria ( true ) ; this . anonymous = ( currentOutliers ) <= ( absoluteMaxOutliers ) ; } private void analyzeSampleBasedCriteria ( boolean earlyAbort ) { } private HashGroupifyEntry createEntry ( final int [ ] key , final int index , final int hash , final int line ) { } private boolean equalsIgnoringOutliers ( final int [ ] a , final int [ ] a2 ) { } private final HashGroupifyEntry findEntry ( final int [ ] key , final int index , final int keyHash ) { } private int isAnonymous ( HashGroupifyEntry entry ) { } private void rehash ( ) { } }

Fix:
if ( ( ( classBasedCriteria . length ) == 0 ) && ( ( sampleBasedCriteria . length ) == 0 ) ) {